Enhancement of intestinal epithelial barrier function by Weissella confusa F213 and Lactobacillus rhamnosus FBB81 probiotic candidates in an in vitro model of hydrogen peroxide-induced inflammatory bowel disease

Objective: Weissella confusa F213 (WCF213) and Lactobacillus rhamnosus FBB81 (LrFBB81) are two probiotic candidates isolated from humans in our previous study. Their functional activity on the mucosal barrier has not yet been adequately investigated. Therefore, the objective of this study was to investigate the effect of these strains on maintaining mucosal integrity in vitro. Caco-2 cell monolayers were pretreated with WCF213 and LrFBB81 before being exposed to hydrogen peroxide. The integrity of mucosal cells was evaluated by measuring the transepithelial resistance (TER), flux of FITC-labelled dextran, and ZO-1 protein distribution with the help of an immunofluorescence method. Results: WCF213 was found to significantly maintain the TER better than the control hydrogen peroxide-treated cells (p < 0.001), followed by the strain combination, and LrFBB81 alone (p < 0.05). The permeability of mucosa was also successfully maintained by the WCF213 strain. This was illustrated by the significant reduction in the flux of FITC-labelled dextran (p < 0.05), which was larger than that exhibited by the other groups. The ZO-1 distribution of strain-treated cells showed less disruption than hydrogen peroxide-treated cells, consistent with the TER and FITC experimental results. These findings indicate that WCF213 and LrFBB81 plays important roles in the maintenance of mucosal integrity in a strain-dependent manner.